This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 11-196701, filed Jul. 9, 1999, the entire contents of which are incorporated herein by reference.
The present invention relates to a compact information-processing device, i.e., a portable electronic device, such as a portable terminal device, or a portable computer. More specifically, the present invention relates to a technique of controlling such an electronic device, when the device is carried into an area where radiation of electromagnetic waves is restricted, such as an airplane, air traffic control facilities, or medial treatment facilities.
For example, in an airplane and air traffic control facilities, radiation of electromagnetic waves from electronic devices carried therein from outside is strictly restricted to guarantee safe service.
Jpn. Pat. Appln. KOKAI Publication No. 10-320668 directed to an electromagnetic wave alarm apparatus discloses a conventional technique of restricting radiation of electromagnetic waves. This apparatus has a function of detecting and reporting that a person carrying a device, which radiates electromagnetic waves, comes within a certain distance. In other words, the apparatus can detect radiation of electromagnetic waves and report it as a warning, before a person carrying a device, which radiates electromagnetic waves, comes to a position where the device disturbs various facilities to be protected.
With the above described technique, it is possible to check, at the entrance gate of facilities, each device to be carried therein, whether it should be subjected to restriction of radiation of electromagnetic waves. However, once they are carried into the facilities, it is impossible to restrict their operation, and thus is difficult to obtain a sufficient check. Furthermore, the devices do not have any function of restraining themselves from radiating electromagnetic waves in areas where radiation of electromagnetic waves is restricted. Accordingly, with the above described technique, although it is possible to detect and report radiation of electromagnetic waves coming closer, it is impossible to shut down the radiation of electromagnetic waves.
An object of the present invention is to provide a portable electronic device with a function of restraining itself from radiating electromagnetic waves in areas where radiation of electromagnetic waves is restricted, so that a reliable environment without any unnecessary electromagnetic waves is created in the areas.
According to a first aspect of the present invention, there is provided a portable electronic device comprising:
a main body which is changeable between a first state where the main body is able to generate a first electromagnetic wave at a first intensity or more, and a second state where the main body is unable to generate the first electromagnetic wave at the first intensity or more;
a detector configured to detect a second electromagnetic wave having a frequency different from that of the first electromagnetic wave; and
a controller configured to set the main body at the second state on the basis of detection by the detector.
According to a second aspect of the present invention, there is provided a portable electronic device having a communicating unit for communicating with another device by using an electro magnetic wave, comprising:
a main body which is changeable between a first state where the main body is able to generate a first electromagnetic wave at a first intensity or more, and a second state where the main body is unable to generate the first electromagnetic wave at the first intensity or more;
a detector configured to detect a second electromagnetic wave radiated from an installation arranged on a passageway to an area where radiation of electromagnetic waves is restricted, the second electromagnetic wave having a frequency different from that of the first electromagnetic wave; and
a controller configured to set the main body at the second state on the basis of detection by the detector.
According to a third aspect of the present invention, there is provided a method of controlling a portable electronic device including a main body which is changeable between a first state where the main body is able to generate a first electromagnetic wave at a first intensity or more, and a second state where the main body is unable to generate the first electromagnetic wave at the first intensity or more, the method comprising the steps of:
detecting by a detector a second electromagnetic wave radiated from an installation arranged on a passageway to an area where radiation of electromagnetic waves is restricted, the second electromagnetic wave having a frequency different from that of the first electromagnetic wave; and
causing a controller to set the main body at the second state on the basis of detection by the detector.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.